Xerophytic Ferns in Ecuador

Abstract

Fences made of wood, or of wire supported between posts, are almost unknown in Ecuador. Fences of rails, pickets, or of boards fastened to upright posts would succumb rapidly to decay and to the ravages of termites. Wire fencing is prohibitively expensive, and even if it were not, the posts upon which the wire is strung would be just as susceptible to fungus and termite damage as those used in constructing an all-wood fence. Add to these deterring factors a scarcity of readily accessible timber in the inter-Andean valley in which many of the larger towns are located, and one quickly understands why earthen walls from one to four feet thick and about seven feet high take the place of fences, as we know them, throughout much of Ecuador. Small suckers or offshoots from mature plants of Agave sisalana and Fourcroya occidentalis, both fiber plants, are planted along the top of many of the tamped earth walls to reduce erosion during the rainy season. (In the towns and cities a capping of tile or of a hard plaster commonly serves the same purpose and does not eventually split the wall with enlarging roots.) The walls upon which the fiber-producing plants grow form excellent habitats for a number of xerophytic or semixerophytic ferns. Practically every earthen wall that has stood through three or more seasons supports from one to a dozen species of ferns. The fern flora on the earthen walls in the larger cities rarely approaches the richness of that on similar walls in the country, for the